The present invention relates to a method and apparatus for machining and finishing bearing balls.
Known methods of working bearing balls attempt to obtain uniform finishing by rolling the ball between two similar grinding disks which are generally rotated about or orbital to their central axes. As a result, during each pass of the ball about the grinding surfaces, a strip or belt is machined on the surface. The ball is worked through a number of passes during which time it is assumed that the ball rolls about a sufficient number of random axes so that it is machined over its entire surface.
The change in rolling axes is generally left to chance; however, in my copending application Ser. No. 760,192, filed Sept. 17, 1968, now U.S. Pat. No. 3,545,139 issued Dec. 8, 1971 there is disclosed an improved method and apparatus for rolling the ball over a regularly changing plurality of meridian paths.
Raw bearing balls deviate from a true sphere and have in fact oval or angular shapes. It has been found that the grinding of raw balls takes considerable time with the known devices and, in fact, results also in the grinding of portions of the surface which do not require grinding to obtain the spherical shape. As a consequence, material time and labor are expended to obtain satisfactorily finished balls.
It is an object of the present invention to provide an improved apparatus for machining bearing balls.
It is another object of the present invention to provide a simple, efficient and economical apparatus for effectively finishing bearing balls.
It is another object of the present invention to provide apparatus which reduces the time and material wasted in finishing bearing balls.
It is a more specific object of the present invention to provide apparatus for obtaining controlled finishing over the entire surface of the bearing ball.